Scattered object collection system

ABSTRACT

Provided is a highly reliable, cost-effective scattered object collection system that can determine the correct position of each scattered object on the ground, such as a ball, and efficiently collect scattered objects by reducing unnecessary traveling of an autonomous collector. The scattered object collection system includes an autonomous collector that performs a collecting operation by picking up balls B while traveling in a work area W and a collector management unit that manages the autonomous collector. The collector management unit acquires positional information on the autonomous collector, identifies an actual position where each ball B was picked up in the work area W using the acquired positional information, and allows the autonomous collector to perform a collecting operation in a place having a high density of balls B with higher priority than a place having a low density of balls B using the identified actual positional information on each ball B.

TECHNICAL FIELD

The present invention relates to a scattered object collection systemincluding an autonomous collector for picking up and collecting objectsthat have fallen and scattered on the ground (i.e., scattered objects),such as golf balls, tennis balls, nuts, and containers, for example,while traveling on the ground. Particularly, the present inventionrelates to a scattered object collection system configured toefficiently collect scattered objects using positional information.

BACKGROUND ART

For example, there is known an autonomous (also referred to as“self-propelled”) ball collector, also called a ball picker and thelike, that collects a number of golf balls scattered on the ground of agolf driving range, for example, while traveling on the ground asdescribed in Patent Literature 1 and 2.

Such a ball collector typically includes, as described in PatentLiterature 1 and 2, a ball collection wheel that picks up balls from theground by rolling on the ground, and a collection tank that receives andstores the balls picked up by the ball collection wheel.

As the ball collector, a motor-driven ball collector, a traction typeball collector, and a hand push ball collector are widely used. As theball collection wheel, the one described in Patent Literature 3 is knownthat includes a predetermined number of discs forming multiple elongatedgrooves including a number of annular grooves, each annular groovehaving a number of ball pockets formed therein at equal angularintervals along the circumferential direction for picking up balls onthe ground.

CITATION LIST Patent Literature

-   Patent Literature 1: JP 2963571 B-   Patent Literature 2: WO 00/78410 A-   Patent Literature 3: JP S50-53061 U-   Patent Literature 4: JP 2008-220935 A-   Patent Literature 5: U.S. Pat. No. 8,972,102 B

SUMMARY OF INVENTION Technical Problem

The conventional scattered object collection system using theabove-described autonomous ball collector performs a ball collectingoperation while traveling all over a work area (i.e., an area where aball may be on the ground) irrespective of whether there is actually aball, and thus has a low efficiency in the ball collecting operation dueto a number of unnecessary traveling of the ball collector.

With a low efficiency in the ball collecting operation, balls may notoften be supplied (i.e., collected) promptly to meet customer demandsfor balls in a hitting bay, and to avoid this, the number of balls instock needs to be increased, for example. This is not cost efficient andmay increase the number of times of charging due to a high batteryconsumption (power consumption) relative to the number of collectedballs, whereby the energy cost may increase and the operation efficiencymay be even lower.

Thus, nowadays, to efficiently perform the ball collecting operation,grasping the correct scattering (i.e., distribution) state of balls, thecorrect dense areas of balls, and the like is considered. For example,as described in Patent Literature 4, there is known a technique ofcollecting ball density distribution information before starting a ballcollecting operation, and performing a ball collecting operationstarting with an area with a high ball distribution rate (i.e., density)while detecting the position of the ball collector in a work area usinga global positioning system (GPS).

However, with the technique described in Patent Literature 4, the balldensity distribution information is created by observing a pattern(i.e., a distribution state) of balls in the work area for a givenperiod of time using a visual sensor, such as a camera, for monitoringthe condition of the work area and another sensor for monitoring thenumber of balls collected in a designated range, for example. Thus, itwould be impossible to acquire the correct actual position where eachball was picked up (i.e., the actual positional information on eachball) that is necessary for creating the ball density distributioninformation. In addition, although the position of the ball collector inthe work area can be detected using a GPS and the like, a specific meansof grasping the actual positional information on each ball using a GPSand the like is unknown.

In addition, in relation to identifying a position of a ball, PatentLiterature 5 describes a vehicle type ball collector configured to usean ID tag embedded in a ball and identify a position of a ball using theID tag embedded ball and a GPS, and then collect balls. However, a ballcollection system using the ID tag embedded balls tends to be extremelyexpensive and is not for a practical use because it is not costeffective.

The present invention has been made in view of the foregoing, andprovides a highly reliable, cost-effective scattered object collectionsystem that can efficiently collect scattered objects by reducingunnecessary traveling of the autonomous collector using positionalinformation.

Solution to Problem

In view of the foregoing, a scattered object collection system accordingto the present invention basically includes an autonomous collector thatperforms a collecting operation by picking up scattered objectsscattered in a work area while traveling in the work area and acollector management unit that manages the autonomous collector, inwhich the collector management unit acquires positional information onthe autonomous collector, identifies an actual position where eachscattered object was picked up in the work area using the acquiredpositional information, and allows the autonomous collector to perform acollecting operation in a place having a high density of scatteredobjects with higher priority than a place having a low density ofscattered objects using the identified actual positional information oneach scattered object.

In one aspect, the autonomous collector may include a sensor fordetecting that scattered objects are present on a ground in the workarea and acquiring positional information on the scattered objects.

In another aspect, the autonomous collector may include a sensor forsequentially detecting that each scattered object has been picked up andcollected and acquiring collection information, and the collectormanagement unit may use the acquired collection information inidentifying an actual position where each scattered object was pickedup.

In still another aspect, the collector management unit may acquire adistribution state of scattered objects in the work area using theactual positional information on each scattered object, and create ascattered object density distribution map including a plurality of denseareas having different densities of scattered objects based on theacquired distribution state.

Advantageous Effects of Invention

Since the scattered object collection system according to the presentinvention can determine the correct position of each scattered object onthe ground, such as a ball, by using positional information and allowsthe autonomous collector to perform a collecting operation in a placehaving a high density of scattered objects with higher priority than aplace having a low density of scattered objects, and thus canefficiently collect scattered objects by reducing unnecessary travelingof the autonomous collector. Therefore, it is possible to provide ahighly reliable, cost-effective scattered object collection system.

BRIEF DESCRIPTION OF DRAWINGS

FIG. 1 is a cross-sectional view of an example of a ball collector as anautonomous collector that is used in one embodiment of a scatteredobject collection system according to the present invention, with a bodycover of the ball collector omitted.

FIG. 2 is a partially enlarged perspective view of a ball collectionwheel in FIG. 1 .

FIG. 3 is an enlarged cross-sectional view of the ball collection wheelin FIG. 1 .

FIG. 4 is a functional block diagram used for illustrating a process ofa controller and a management server provided in the ball collector ofan embodiment.

FIG. 5 is a view used for illustrating a distribution state of balls ina work area of an embodiment.

FIG. 6 is a view illustrating a ball density distribution map createdbased on the distribution state of balls in FIG. 5 of an embodiment.

FIG. 7 is a diagram used for illustrating a ball density distributionmap when created by computer processing of an embodiment.

FIG. 8 is a view used for illustrating a travel ratio in each area of anembodiment.

FIG. 9 is a flowchart used for illustrating the travel ratio in eacharea of an embodiment.

FIG. 10 is a schematic view illustrating a state where an autonomousball collector is performing a collecting operation while patterntraveling.

FIG. 11 is a schematic view illustrating a state where an autonomousball collector is performing a collecting operation while randomtraveling.

DESCRIPTION OF EMBODIMENTS

Hereinafter, one embodiment of the present invention will be describedwith reference to the drawings.

FIG. 1 is a schematic configuration diagram of an example of a ballcollector as an autonomous collector that is used in one embodiment of ascattered object collection system according to the present invention.FIG. 2 is a partially enlarged perspective view of a ball collectionwheel in FIG. 1 . FIG. 3 is an enlarged cross-sectional view of the ballcollection wheel in FIG. 1 .

A ball collector 1 illustrated in FIG. 1 is an unmanned autonomous ballcollector and is adapted to collect balls on the ground where a numberof balls are scattered while traveling on the ground. The ball collector1 is typically used for collecting a number of golf balls scattered onthe ground of a golf driving range.

The ball collector 1 includes a traveling body 6 as a body movable onthe ground, a ball collection wheel 5, a ball releasing member (alsoreferred to as a squeezer) 7, a collection tank 8, and a body cover (notillustrated) that covers them.

The traveling body 6 includes a frame 9, a pair of right and left drivewheels 10 disposed on the rear of the frame 9, drive motors 15 thatdrive the drive wheels 10, a battery 14 as a power supply for the drivemotors 15 and the like, a pair of right and left steering wheels 12disposed on the front of the frame 9, and a steering adjustment unit 13that controls the steering wheels 12, for example. As the drive wheels10 are rotationally driven by the drive motors 15, the traveling body 6moves and is automatically controlled in accordance with a predeterminedprogram, whereby the traveling direction or the like of the travelingbody 6 is automatically changed so that the traveling body 6 can travelacross the entire area necessary for collecting balls.

A signal receiving unit 44 having an antenna for receiving a signal froma satellite positioning system, such as a GPS, to acquire positionalinformation is provided above the drive motors 15, the battery 14, andthe like and below the body cover (not illustrated). A controller 50(described in detail later) that performs traveling control and the likeis provided adjacent to the signal receiving unit 44. The controller 50is functionally provided with, for example, a positional informationacquisition unit 54 (FIG. 4 ) that acquires positional information(i.e., latitude and longitude information) on the ball collector 1 basedon a signal received by the signal receiving unit 44.

The ball collection wheel 5 is disposed between the pair of steeringwheels 12 and the pair of drive wheels 10 in the front-rear direction ofthe ball collector 1. The ball collection wheel 5 is rotatable about theaxis X extending in the right-left direction of the traveling body 6,and is supported by the frame 9 such that the outer peripheral face ofthe ball collection wheel 5 is always in contact with the ground G underits own weight. The ball collection wheel 5 collects a number of balls Bscattered on the ground G while rolling on the ground G as the travelingbody 6 moves forward.

As illustrated in FIG. 2 , the ball collection wheel 5 has on its outercircumference multiple elongated grooves 16 in annular shapes (includinga number of annular grooves 17). The annular grooves 17 forming themultiple elongated grooves 16 have ball pockets 18, continuously formedtherein in the circumferential direction, for allowing entry and exit ofballs B due to their elasticity. Each ball pocket 18 has a size capableof holding only one ball B as illustrated in FIG. 1 . In addition, theball pockets 18 of the adjacent annular grooves 17 are formed such thatthey are displaced from each other by a predetermined angle in thecircumferential direction of the annular grooves 17.

The ball collection wheel 5 is formed by an aggregate of a number ofdiscs 19 with an identical configuration, and the annular grooves 17 areformed at equal intervals between the adjacent discs 19. Each disc 19has on one face a plurality of attachment shaft portions 21 each havinga spacer 20, and has on the other face shaft portion receiving holes(not illustrated) for receiving the attachment shaft portions 21. Theattachment shaft portions 21 and the shaft portion receiving holes ofthe adjacent discs 19 are coupled together so that a number of discs 19are integrated at equal intervals. The annular grooves 17 are formed bythe spacers 20 between the adjacent discs 19. Each disc 19 has formed atits center a boss portion 23 for receiving a support shaft 22 (see FIG.1 ), and an aggregate of the boss portions 23 form a support-shaftinsertion hole 24 in the ball collection wheel 5. The support shaft 22(see FIG. 1 ) that is inserted through the support-shaft insertion hole24 is rotatably supported by the frame 9.

As can be seen in FIG. 3 , the ball releasing member 7 is a pectinatemember as a whole, and includes a proximal portion 25 extending in theright-left direction of the traveling body 6, and a number of ballreleasing protrusions 26 extending from the proximal portion 25 inparallel with each other at equal intervals. The gap between the ballreleasing protrusions 26 is identical to the gap between the discs 19(that is, the annular grooves 17) of the ball collection wheel 5. Theproximal portion 25 of the ball releasing member 7 is fixed to the frame9 around a position above the ball collection wheel 5, and each ballreleasing protrusion 26 protrudes into each annular groove 17 of theball collection wheel 5. That is, the pectinate ball releasing member 7is disposed such that it protrudes into each of the annular grooves 17forming the multiple elongated grooves 16.

The lower face of the proximal portion 25 of the ball releasing member 7has a contact-type count sensor 27, which counts the number of balls Breleased from the ball pockets 18 by the ball releasing protrusions 26,fixed thereto by a method such as bonding. The count sensor 27 iscomposed of a single elongated plate-like pressure sensor using apiezoelectric element, and extends in the right-left direction along theproximal portion 25 of the ball releasing member 7 so as to straddleeach of (all) the annular grooves 17 and it has a length correspondingto the length of the ball collection wheel 5 in the axial direction. Thecount sensor 27 is disposed on the trajectories of balls B that areguided in the radiation direction of the ball collection wheel 5 (or thediscs 19 thereof) by the ball releasing protrusions 26 of the ballreleasing member 7, and elongated partitioning protrusions 31 which areformed in the radiation direction on both side of each disc 19 andpartition each annular groove 17 at equal angular intervals in thecircumferential direction so as to define the ball pockets 18.Therefore, the balls B released from the ball collection wheel 5 by theball releasing member 7 surely touch the count sensor 27. Accordingly,the balls B are accurately counted by the count sensor 27. The countsensor 27 may be a non-contact-type counter sensor.

Although the count sensor 27 in the present embodiment is composed of asingle pressure sensor disposed straddle each of (all) the annulargrooves 17, the count sensor 27 may include individual (a plurality of)pressure sensors disposed corresponding to the respective annulargrooves 17. In addition, the count sensor 27 may be disposed at aportion other than the ball releasing member 7.

The collection tank 8, which includes a bottom plate 8 a, side plates 8b, and a front plate 8 d, for example, is disposed behind the ballreleasing member 7. The side plates 8 b of the collection tank 8 aresupported by the frame 9 of the traveling body 6, and accommodate ballsB that are released from the ball collection wheel 5 by the ballreleasing member 7. The bottom plate 8 a of the collection tank 8 isattached in a manner translatable in the vertical direction. When thebottom plate 8 a is moved to a ball discharge position at a lower level,a gap is produced between the bottom plate 8 a of the collection tank 8and a back plate 28 so that balls B are discharged through the gap. Inaddition, a full tank detector (not illustrated) for detecting that thecollection tank 8 is full of a plurality of collected balls B isprovided (swingably) on the collection tank 8.

With such a configuration, as illustrated in FIG. 3 , when the travelingbody 6 moves forward, the ball collection wheel 5, which is rotatableand is always in contact with the ground G, rotates in acounterclockwise direction as seen in FIG. 3 . Accordingly, a number ofballs B scattered on the ground G enter the ball pockets 18 and are heldtherein due to the elastic deformation property of the ball pockets 18(that is, the balls B on the ground are picked up). The balls B held inthe ball pockets 18 are transferred upward with the rotation of the ballcollection wheel 5 along with the forward movement of the traveling body6, and are then pushed against the ball releasing protrusions 26 of theball releasing member 7. Then, with a further rotation of the ballcollection wheel 5, the balls B in the ball pockets 18 are guided upwardalong the elongated partitioning protrusions 31 at the rear portion ofthe ball collection wheel 5 in the rotation direction. Then, aftertouching the count sensor 27 attached to the lower face of the proximalportion 25 of the ball releasing member 7, the balls B are sent to thecollection tank 8 and fall therein.

It should be noted that the ball collector 1 is provided with amechanism (not illustrated) for supporting the ball collection wheel 5while elevating it from the ground. When the aforementioned ballcollecting operation is not performed, such as when the collection tank8 has become full and returns to a predetermined storage space 66 orduring a change in the direction, such as a U-turn, for example, theball collection wheel 5 is elevated from the ground.

In addition to the aforementioned configuration, in the scattered objectcollection system of the present embodiment, as illustrated in FIG. 4 ,the controller 50 is provided in the ball collector 1 and a managementserver 70 including a PC, for example, is provided outside of the ballcollector 1. The controller 50, the management server 70, and the likeform a collector management unit 80 for managing a ball collectingoperation by the ball collector 1.

The controller 50 includes a CPU, an input/output circuit, and a storageunit (e.g., ROM, RAM, nonvolatile memory, HDD, and SSD). The storageunit stores programs and various data. By executing a predeterminedprogram stored in the storage unit, the controller 50 functions as adesired functional processor for controlling autonomous travel oracquiring positional information, for example.

The ball collector 1 (i.e., the controller 50) and the management server70 are provided with a transmission/reception unit (not illustrated) forconnecting them to each other via a wireless network (e.g., a wirelessLAN).

In the scattered object collection system of the present embodiment, theball collector 1 is configured to pick up balls on the ground with theball collection wheel 5 and collect them into the collection tank 8while performing pattern traveling (FIG. 10 ) or random traveling (FIG.11 ) from a start point S to an end point E as appropriate along atraveling path R within the work area W (FIG. 5 ) where balls areexpected to be scattered that is set beforehand.

Herein, it is a primary object of the present embodiment to improve theefficiency in the ball collecting operation, and the following schematicconfiguration is employed to achieve the primary object. That is, thescattered object collection system identifies an actual position whereeach ball was picked up in the work area W using a signal received bythe signal receiving unit 44 and a detection signal obtained by thecount sensor 27, acquires a distribution state of balls in the work areaW using the identified actual positional information on each ball,creates a ball density distribution map including a plurality of denseareas having different ball densities based on the acquired distributionstate of balls, and allows the ball collector 1 to travel to perform acollecting operation in a place having a high density of balls withhigher priority than a place having a low density of balls, morespecifically, such that the place having a high density of balls has ahigher travel ratio (e.g., travel time or travel distance) of the ballcollector 1 than that of the place having a low density of balls, usingthe created ball density distribution map.

It should be noted that, in addition to the primary object, to increasethe control accuracy, the scattered object collection system of thepresent embodiment is configured to correct the positional informationon the ball collector 1 at a time point when a ball was counted bytouching the count sensor 27, and thus acquire the actual position wherethe ball was picked up (i.e., the actual positional information on theball).

This will be briefly described with reference to FIG. 3 . A position(i.e., a ball Be) at a time point when a ball has touched the countsensor 27 and a signal (i.e., level) from the count sensor 27 has thusexceeded a predetermined threshold, that is, a time point when a ball isrecognized as having been picked up based on a signal from a satellitepositioning system, such as a GPS, to acquire positional information isaway from the actual position (i.e., a ball Ba) where the ball waspicked up. That is, by the time a ball touches the count sensor 27 afterhaving been picked up from the ground by the ball collection wheel 5,the ball collector 1 has moved by the length La of the outercircumferential arc of the ball collection wheel 5 corresponding to thecentral angle θ formed by the ball Ba—the support shaft 22—the ball Be.It follows that the positional information includes an errorcorresponding to the movement distance La of the ball collector 1 in itstraveling direction. Thus, the positional information is to be corrected(described in detail later).

The scattered object collection system of the present embodiment havingsuch a schematic configuration will be described in detail below.

In the present embodiment, the scattered object collection systemincludes the collector management unit 80 including the controller 50,the management server 70, and the like to manage the ball collector 1.The controller 50, as illustrated in a functional block of FIG. 4 , isfunctionally provided with a timer unit 51, a rotational speedcalculation unit 52, a ball counting unit 53, a positional informationacquisition unit 54, a to-be-corrected information acquisition unit 56,a ball position identification unit 57, a positional information storageunit 58, and a traveling control unit 60.

The timer unit 51 starts timing when the controller 50 is powered ON(i.e., started), continuously measures the elapsed time while thecontroller 50 is ON, and terminates the timing when the controller 50 ispowered OFF. The measurement unit of the timer unit 51 is 10 μs, forexample. The elapsed time from when the controller 50 is started,corresponding to the “time,” can be obtained from the timer unit 51 inunits of one hundred-thousandth of a second.

The rotational speed calculation unit 52 calculates the rotational speedof the ball collection wheel 5 (or its equivalent traveling speed of theball collector 1) based on a signal from a disc number-of-revolutionssensor 43 that detects the rotational speed of the discs 19, and sendsthe calculated rotational speed (or the traveling speed) to theto-be-corrected information acquisition unit 56.

The ball counting unit 53 determines if a signal from the count sensor(i.e., the pressure sensor) 27 has exceeded a predetermined threshold,and if so, determines that balls have been collected and thus counts thenumber of the collected balls, and then sends to the to-be-correctedinformation acquisition unit 56 information that the balls have beencounted as well as the time point when the signal has exceeded thethreshold. Furthermore, when a ball count (e.g., the number of ballscounted) has reached a given number (i.e., when the collection tank isestimated to have become full) during the ball collecting operation, theball counting unit 53 sends to the traveling control unit 60 informationindicating so. It should be noted that the ball counting unit 53 sendsalso to the management server 70 the ball count (e.g., the number ofballs counted) and information that the collection tank is full ofcollected balls, for example.

The positional information acquisition unit 54 acquires the positionalinformation on the ball collector 1 at predetermined time intervals(e.g., every one-hundredth of a second) based on a signal received bythe signal receiving unit 44, and sends the acquired positionalinformation to the to-be-corrected information acquisition unit 56.

The to-be-corrected information acquisition unit 56 acquires informationfor correcting the positional information on the ball collector 1 at atime point when balls were counted by touching the count sensor 27, inorder to determine the actual position where the balls were picked up.As the information for correcting the positional information on the ballcollector 1, the following are used, for example: the movement distanceLa of the ball collector 1 from the time each ball was picked up fromthe ground by the ball collection wheel 5 till the ball was counted bytouching the count sensor 27; the length of time Ja taken for each ballto be counted by touching the count sensor 27 after having been pickedup from the ground by the ball collection wheel 5; positionalinformation acquired from the positional information acquisition unit54; the traveling direction of the ball collector 1; and the travelingspeed of the ball collector 1 or the rotational speed of the ballcollection wheel 5.

The ball position identification unit 57 corrects the positionalinformation on the ball collector 1 at a time point when balls werecounted by touching the count sensor 27, using the information acquiredby the to-be-corrected information acquisition unit 56, therebyacquiring the actual position where the balls were picked up (i.e., theactual positional information on the balls).

Specifically, the actual position where each ball was picked up isdetermined using the movement distance La of the ball collector 1 fromthe time each ball was picked up from the ground by the ball collectionwheel 5 till the ball was counted by touching the count sensor 27, orthe length of time Ja taken for each ball to be counted by the countsensor 27 after having been picked up from the ground by the ballcollection wheel 5.

For example, based on the positional information on the ball collector 1at a time point when each ball was counted by touching the count sensor27, the movement distance La of the ball collector 1 from the time eachball was picked up from the ground by the ball collection wheel 5 tillthe ball was counted by touching the count sensor 27 is reflected(returned) in the direction opposite to the traveling direction of theball collector 1 at that time, whereby the actual position where eachball was picked up is determined.

Alternatively, for example, the positional information on the ballcollector 1 at a time point earlier than the time point when each ballwas counted by touching the count sensor 27 by the length of time Ja,which was taken for each ball to be counted by touching the count sensor27 after having been picked up from the ground by the ball collectionwheel 5, is obtained, and the obtained positional information isdetermined to be the actual position where each ball was picked up.Accordingly, it is possible to determine the correct position of eachball on the ground.

The positional information storage unit 58 stores the actual positionalinformation on the balls corrected by the ball position identificationunit 57, and sends the stored actual positional information on the ballsto the management server 70. The sending timing may be any of thefollowing: each time a ball is collected, at a time when the ballcollector 1 has returned to the station 65, and at a time when theoperation has finished. It should be noted that the actual positionalinformation on the balls may be stored in an external storage device,such as a memory card that is insertable into and removable from thecontroller 50, for example, other than being sent to the managementserver 70 for the ball collector 1 and stored therein as describedabove.

The traveling control unit 60 performs steering control, speed control,and the like by sending control signals to drive circuits 62 of theright and left drive motors 15 and the like so that the ball collector 1travels in accordance with a ball density distribution map describedlater, an operation schedule, or the like, which are sent from themanagement server 70. In addition, upon receiving from the ball countingunit 53 information indicating that a ball count (e.g., the number ofballs counted) has reached a given number, the traveling control unit 60causes the ball collector 1 to stop the ball collecting operation anddirects the ball collector 1 to the nearest storage space 66 so as tounload the balls in the collection tank 8 into the nearest storage space66, and then resume the ball collecting operation. It should be notedthat when the traveling control unit 60 directs the ball collector 1 tothe storage space 66, the battery 14 is charged at the chargingequipment 67 provided beside the storage space 66, as appropriate.

Meanwhile, the management server 70, as illustrated in the functionalblock of FIG. 4 , is functionally provided with a ball distributionstate acquisition unit 71, a ball density distribution map creation unit72, and an operation management unit 75, and is connected to an inputdevice 77 (e.g., a mouse, a touch pen, a keyboard, or a touchpad) and adisplay device 78.

The ball distribution state acquisition unit 71, as exemplarilyillustrated in a schematic view of FIG. 5 , plots ∘, for example, oneach of the actual positions (i.e., latitude and longitude) of the ballsB in the work area W, using the actual positional information on theballs, which is sent from the positional information storage unit 58,thereby acquiring a distribution state of balls.

Based on the distribution state of balls, the ball density distributionmap creation unit 72 creates a ball density distribution map M includingthree areas: a high-density area Ma (i.e., an area in which balls aredensely present), a low-density area Mb (i.e., an area in which ballsare not so densely present), and a non-dense area Mc (i.e., an area inwhich balls are hardly densely present). It is needless to mention thatthe division of the ball density distribution map M is not limitedthereto.

The ball density distribution map M may be manually created by a user orautomatically created by computer processing. In the present embodiment,a user can select the way of creation by operating the input device 77.

When the ball density distribution map M is manually created by a user,images (∘) of the balls B are displayed on the screen of the displaydevice 78 as illustrated in FIG. 5 , and the user, as illustrated inFIG. 6 , inputs with the input device 77 a line surrounding a group ofballs B that are relatively densely present as visually seen and sets aclosed area surrounded by the line as the high-density area Ma. Then,the user inputs a line surrounding a group of balls B that arerelatively not so densely present outside of the high-density area Maand sets a portion of a closed area surrounded by the line, excludingthe high-density area Ma (the closed area itself as input when there isno high-density area Ma in the closed area), as the low-density area Mb,and sets a portion of the work area W, in which balls B are hardlydensely present, excluding the high-density area Ma and the low-densityarea Mb, as the non-dense Mc.

When the ball density distribution map M is automatically created bycomputer processing, as exemplarily illustrated in a conceptual view ofFIG. 7 for setting the high-density area Ma, the work area W in whichthe images (∘) are plotted on the actual positions (i.e., latitude andlongitude) of the balls B is divided into unit sections, each having(width X1 in the X direction)×(width Y1 in the Y direction), and thenumber of balls B in each unit section is counted. A closed area (i.e.,hatched area) consisting of consecutive adjacent unit sections, in whichthe number of balls per unit section is equal to or larger than a setnumber (α), is set as the high-density area Ma. Likewise, a portion of aclosed area consisting of consecutive adjacent unit sections, in whichthe number of balls per unit section is equal to or larger than a setnumber (β that is smaller than α), excluding the high-density area Ma(the closed area itself as calculated when there is no high-density areaMa in the closed area), is set as the low-density area Mb. A portion ofthe work area W, in which balls B are hardly densely present, excludingthe high-density area Ma and the low-density area Mb, is set as thenon-dense Mc.

Data on the ball density distribution map M created in this manner issent to the operation management unit 75 as well as to the travelingcontrol unit 60 of the controller 50.

It should be noted that examples of the method for setting thehigh-density area Ma or the like by computer processing may includeidentifying an aggregate of balls having a distance between two adjacentballs being equal to or smaller than a set distance and setting theaggregate of balls as the high-density area Ma or the like, identifyingan area having a largest number of balls or ball density in an area(size) set beforehand, such as a high-density area Ma, and setting thearea having a largest number of balls or ball density as thehigh-density area Ma or the like, for example, other than using thenumber of balls per predetermined unit section as described above.

In order to improve the efficiency in the ball collecting operation, theoperation management unit 75 plans an operation schedule (or a programthereof) and a traveling method/traveling aspect of the ball collector 1using the created ball density distribution map M such that an areahaving a high density of balls is given higher priority than an areahaving a low density of balls, more specifically, such that the areahaving a high density of balls has a higher travel ratio (e.g., traveltime or travel distance) of the ball collector 1 than that of the areahaving a low density of balls, and then sends the plan for each day, forexample, to the controller 50 before starting a collecting operation onthe day.

The controller 50 (or the traveling control unit 60 thereof) controlsthe ball collector 1 to be directed to the target area (Ma, Mb, Mc) andperform pattern traveling (FIG. 10 ) or random traveling (FIG. 11 ) froma start point S to an end point E as appropriate along a traveling pathR in accordance with the operation schedule or the like that is sentfrom the management server 70. Accordingly, while traveling, the ballcollector 1 picks up the balls on the ground with the ball collectionwheel 5 and collects them into the collection tank 8.

Herein, examples of the method for setting a higher travel ratio (e.g.,travel time or travel distance) of the ball collector 1 in an areahaving a high density of balls than in an area having a low density ofballs, may include, in the collecting operation during patterntraveling, as illustrated in FIG. 8 , for example, minimizing a returnwidth D when the ball collector 1 passes through the high-density areaMa (e.g., corresponding to a width slightly smaller than a lateral widthof the ball collection wheel 5), slightly expanding the return width Dwhen the ball collector 1 passes through the low-density area Mb (e.g.,corresponding to a width larger than the lateral width of the ballcollection wheel 5), and further expanding the return width D when theball collector 1 passes through the non-dense area Mc.

With this configuration, the travel ratio (e.g., travel time or traveldistance) of the ball collector 1 is low in an area in which balls arenot so densely present or an area in which balls are hardly denselypresent.

In addition, examples of the method for setting a higher travel ratio(e.g., travel time or travel distance) of the ball collector 1 in anarea having a high density of balls than in an area having a low densityof balls, may include adjusting an operation schedule such that the areahaving a high density of balls has a more number of times of operation(provided that the number of times of operation in a target area countsas 1 when the collecting operation while traveling across the entiretarget area has finished) than that of the area having a low density ofballs, other than changing the traveling method/traveling aspect by, forexample, adjusting the return width D in pattern traveling as describedabove.

A program of this method will be described with reference to theflowchart of FIG. 9 . This program is executed repeatedly inpredetermined cycles.

Herein, first in steps S111 and S112, while traveling across everywhereonly the high-density area Ma, the ball collector 1 performs thecollecting operation once. The traveling method may be either patterntraveling or random traveling (the same applies hereinafter).

Next in steps S113 and S114, while traveling across the inside of thelow-density area Mb, that is, everywhere the high-density area Ma+thelow-density area Mb, the ball collector 1 performs the collectingoperation once. This means that the ball collector 1 has finished thecollecting operation in the high-density area Ma twice, and thecollecting operation in the low-density area Mb once.

Next in steps S115 and S116, while traveling across the inside of thework area W (i.e., the inside of the non-dense area Mc), that is,everywhere the high-density area Ma+the low-density area Mb+thenon-dense area Mc, the ball collector 1 performs the collectingoperation once. This means that the ball collector 1 has finished thecollecting operation in the high-density area Ma three times, thecollecting operation in the low-density area Mb twice, and thecollecting operation in the non-dense area Mc once.

It should be noted that the number of times of collecting operation orthe travel time may vary among steps S111 and S112, steps S113 and S114,and steps S115 and S116 or the return width D in pattern traveling maybe adjusted in the respective steps such that the area having a highdensity of balls has a higher travel ratio (e.g., travel time or traveldistance) of the ball collector 1 than that of the area having a lowdensity of balls.

As is clear from the aforementioned description, the scattered objectcollection system of the present embodiment identifies an actualposition where each ball was picked up in the work area W using a signalreceived by the signal receiving unit 44 and a detection signal obtainedby the count sensor 27, acquires a distribution state of balls in thework area W using the identified actual positional information on eachball, creates a ball density distribution map M including three areashaving different ball densities: the high-density area Ma, thelow-density area Mb, and the non-dense area Mc based on the acquireddistribution state of balls, and allows the ball collector 1 to travelto perform a collecting operation in a place having a high density ofballs with higher priority than a place having a low density of balls,more specifically, such that the place having a high density of ballshas a higher travel ratio (e.g., travel time or travel distance) of theball collector 1 than that of the place having a low density of balls,using the created ball density distribution map M. This reducesunnecessary traveling of the ball collector 1 and improves theefficiency in the ball collecting operation.

With an increased efficiency in the ball collecting operation, it ispossible to achieve reduction in operation costs of a facility, such asreduction of the number of balls in stock, for example, and reduce thenumber of times of charging due to a low battery consumption (powerconsumption) relative to the number of collected balls, whereby theenergy cost can be low.

It should be noted that the controller 50 of the ball collector 1 mayperform the acquiring of a distribution state of balls, the creating ofa ball density distribution map and the like, or an operator may performthem based on the actual positional information on the balls and theninput information to the controller 50 of the ball collector 1 and themanagement server 70.

The aforementioned embodiment illustrates an example in which the ballcollector 1 includes the count sensor 27 for counting the number ofballs in the collection tank 8 as a sensor for detecting that eachpicked-up ball has been collected (i.e., detecting the position of eachcollected ball), at a position detected by a satellite positioningsystem, such as a GPS, for example, and the count sensor 27 sequentiallydetects that each ball has been collected and identifies the position ofthe ball. Alternatively, the ball collector 1 may include a weightsensor for measuring the weight of each ball in the collection tank 8and another sensor so that the weight sensor detects that each ball hasbeen collected and the other sensor identifies the position of the ball.As a further alternative, the ball collector 1 may include a sensor forcounting the number of balls in the collection tank 8 and another sensorso that the former sensor detects that each ball has been collected andthe latter sensor identifies the position of the ball. For such sensors,a physical detection method using a button, a detection method using alaser, or a detection method using a camera image is considered, forexample. In addition, it is desirable that any balls be detectable evenif they are not expensive ones with built-in IC chips. In that case, theaforementioned sensor is preferably used to detect that each ball hasbeen collected. In particular, the ball collector 1 is preferably anunmanned autonomous ball collector.

The place (i.e., area) where the ball collector 1 is used, the types ofballs to be collected, and the like are not limited to theaforementioned examples.

Although the aforementioned embodiment illustrates examples in which theobjects to be collected (i.e., scattered objects) are golf balls thathave been struck and scattered on the ground in the golf driving range,the present embodiment is not limited thereto and is similarlyapplicable when the objects to be collected (i.e., scattered objects)are balls scattered on the ground in a sports facility, such as tennisballs or baseballs, nuts, or containers, for example.

Although the embodiment of the present invention has been described indetail above, the specific configuration is not limited thereto, and anydesign changes and the like that are within the spirit and scope of thepresent invention are encompassed by the present invention. In addition,the techniques of the aforementioned embodiment can be combined asappropriate as long as there is no contradiction or problem in theobjects, configurations, or the like of the embodiment.

REFERENCE SIGNS LIST

-   1 Ball collector (autonomous collector)-   5 Ball collection wheel (collection member)-   6 Traveling body-   7 Ball releasing member-   8 Collection tank-   19 Disc-   27 Count sensor-   43 Disc number-of-revolutions sensor-   44 Signal receiving unit-   50 Controller-   51 Timer unit-   52 Rotational speed calculation unit-   53 Ball counting unit-   54 Positional information acquisition unit-   56 To-be-corrected information acquisition unit-   57 Ball position identification unit-   58 Positional information storage unit-   60 Traveling control unit-   65 Station-   66 Storage space-   67 Charging equipment-   70 Management server-   71 Ball distribution state acquisition unit-   72 Ball density distribution map creation unit-   75 Operation management unit-   77 Input device-   78 Display device-   80 Collector management unit-   W Work area-   M Ball density distribution map (scattered object density    distribution map)-   Ma High-density area-   Mb Low-density area-   Mc Non-dense area

1. A scattered object collection system comprising: an autonomouscollector that performs a collecting operation by picking up scatteredobjects scattered in a work area while traveling in the work area; and acollector management unit that manages the autonomous collector, whereinthe collector management unit acquires positional information on theautonomous collector, identifies an actual position where each scatteredobject was picked up in the work area using the acquired positionalinformation, and allows the autonomous collector to perform a collectingoperation in a place having a high density of scattered objects withhigher priority than a place having a low density of scattered objectsusing the identified actual positional information on each scatteredobject.
 2. The scattered object collection system according to claim 1,wherein the autonomous collector includes a sensor for detecting thatscattered objects are present on a ground in the work area and acquiringpositional information on the scattered objects.
 3. The scattered objectcollection system according to claim 1, wherein the autonomous collectorincludes a sensor for sequentially detecting that each scattered objecthas been picked up and collected and acquiring collection information,and the collector management unit uses the acquired collectioninformation in identifying an actual position where each scatteredobject was picked up.
 4. The scattered object collection systemaccording to claim 1, wherein the collector management unit isconstituted of a controller provided in the autonomous collector and/ora management server for the autonomous collector.
 5. The scatteredobject collection system according to claim 1, wherein the collectormanagement unit acquires a distribution state of scattered objects inthe work area using the actual positional information on each scatteredobject, and creates a scattered object density distribution mapincluding a plurality of dense areas having different densities ofscattered objects based on the acquired distribution state.
 6. Thescattered object collection system according to claim 5, wherein thecollector management unit creates the scattered object densitydistribution map based on at least one of positional information on eachscattered object, respective sizes of the plurality of dense areas setbeforehand, or a size of a unit section set beforehand to measure adensity of the scattered objects.
 7. The scattered object collectionsystem according to claim 6, wherein the collector management unitallows the autonomous collector to preferentially perform a collectingoperation in a dense area representing a relatively high density ofscattered objects among the plurality of dense areas based on thescattered object density distribution map.
 8. The scattered objectcollection system according to claim 1, wherein the collector managementunit allows the autonomous collector to travel to perform a collectingoperation such that a place having a high density of scattered objectshas a higher travel ratio of the autonomous collector than that ofanother place.
 9. The scattered object collection system according toclaim 1, wherein the scattered objects are balls scattered on a groundin a sports facility.
 10. The scattered object collection systemaccording to claim 1, wherein the autonomous collector is used forcollecting balls that have been struck and scattered on a ground in agolf driving range.